Mulching is great! IT will prevent new peony roots from heaving out of the ground during periods of freeze and thaw. Keeping the soil warm (over 40F) will help the peony to grow feeder roots. You don't have to do anything now until spring. When the peonies begin growing in early spring, you can brush aside the mulch to help the young pips grow and prevent fungal disease.

Thank you so much! I feel much better and relieved I don't have to undo the work done!

I mulch my peonies as well, R Perry. Just gently move it away from the growing pips in the spring as Karen advised, they'll do great!